This invention relates to the rinsing of surface-treated articles, and more particularly to a counterflow spray rinse process for surface-treated articles.
Articles, whose surfaces have been chemically or electrochemically treated, such as by electroplating or galvanizing, require rinsing in order to remove the residue or adhering substances from the articles, before further processing.
It is known in the art to utilize a plurality of rinse tanks filled with water so that the chemically treated article is rinsed in stages to gradually remove the concentrated solution or residue. In such a process, the first rinse tank gradually becomes more concentrated than each subsequent rinsing tank, because more residue is removed from the article in the first rinse tank than in any subsequent rinse tank. Eventually, the rinse tank has to be drained and refilled with substantially pure water. Moreover, as the original processing bath continues to receive and treat the article with the concentrated solution, the original processing solution becomes diluted, and the chemicals have to be replenished and the excess water removed, usually by draining. Sometimes the water is removed by evaporation.
It is also known in the the art to re-cycle the rinse water by processing it in an ion-exchange installation in order to detoxify the water. However, such recovery processes are expensive.
Other methods of rinsing articles whose surfaces have been treated with chemical or elector-chemical processes are shown in the following U.S. Pat. Nos:
3,734,108--Almegard et al--May 22, 1973 PA1 4,452,264--Kreisel et al--June 5, 1984 PA1 129,353--Lytle--July 16, 1872 PA1 1,072,562--DeLissaBerg--Sept. 9, 1913 PA1 2,171,402--Muir--Aug. 29, 1939 PA1 3,552,884--Faldi--Jan. 5, 1971
Both the Almegard and Kreisel patents disclose as prior art, a counterflow process, in which water flows in a cascade arrangement serially from one rinse tank to another in the direction opposite the movement of the treated article, so that the water in the rinse tank closer to the treatment tank becomes progressively enriched with the residual substance. When numerous rinse tanks are employed in the counterflow cascade process, pumps must be utilized in order to pump the water from one tank to the next. In such a cascade process, although conserving fresh water, the pumping of such large volumes of water becomes expensive.
Both the Almegard and Kreisel patents also disclose that it is old to spray-rinse an article whose surface has been chemically or electro-chemically treated. However, the spray processes disclosed in both Almegard and Kreisel utilize a single spraying chamber, and in some instances, the spray chamber is made mobile so that it can be utilized to spray-rinse articles at several different treatment tanks.
However, neither Amegard nor Kreisel, nor any other prior art known to the applicant, discloses a rinse process incorporating a pulse spray counterflow principle which is most applicable for rinsing chemically or electro-chemically treated articles, such as copper-, nickel-, zinc-, or chrome-plated articles.
Submersible pumps having a pump chamber with an inlet check valve for receiving a fluid in which the pump chamber is submerged, and also provided with a compressed air inlet for receiving compressed air to discharge the fluid from the pumps, are well known in the art, as shown in the following U.S. Pat. Nos:
However, none of the above patents disclose the above submersible pumps used in combination with a counterflow spray rinse process for surface treated articles.